I read somewhere that the average human has 0.1 milligrams of uranium in their body. How did it get there, and does it do anything?

Question

I read somewhere that the average human has 0.1 milligrams of uranium in their body. How did it get there, and does it do anything?

In: Biology

Answer 1

Uranium is everywhere, it’s a naturally occurring element, making up 2.8 parts per million in the Earth’s crust. For a 100kg person (100,000,000 mg) that ratio would be 2.8g. So humans have less uranium than the average chunk of dirt. It’s mostly in bones, slowly decomposing, not doing much harm. You get it from dirt on/in food, and the body has mechanisms that eliminate most of it in urine, that’s how you keep your “less than dirt” concentration.